SANITARY SEWER EVALUATION STUDIES
Comprehensive Assessment of Sanitary Sewer Systems
Aging sewer systems which pre-date the 1970's era are becoming a heavy burden for municipal water authorities as they attempt to keep up with deteriorating sanitary pipes and struggle to maintain systems at or above their maximum hydraulic capacity. To better understand a deteriorating sewer system as well as the areas and population it serves, WRMA performs Sanitary Sewer Evaluation Studies (SSES). During a typical SSES, which is a comprehensive assessment of a sewer system, WRMA will perform hydraulic modeling to gauge the hydraulic demand and identify both hydraulically strong and weak areas of the system which are underperforming due to changes in the environment, defected pipes (I&I), or growth in population. For sewer systems which are located or travel through rural and wooded areas, a WRMA SSES study may also include trunkwalks of the sewer mains greater than or equal to 15 inches in diameter as these pipes carry large flows and are under heavy loads in the morning and early evenings. During a trunkwalk, WRMA inspectors may locate and identify manholes or pipes that have become or exposed or show signs of prior or recurring sanitary sewer overflow (SSO) events. Following an assessment of trunkwalk data as well as traditional CCTV inspection of sewer mains and manholes, SSES studies can provide reliable data upon which a comprehensive rehabilitation program can be designed to reduce Infiltration and Inflow (I&I) and improve hydraulic capacity. Additionally, SSES studies can provide a basis and rationale for building new infrastructure or making modifications to existing infrastructure to address hydraulic capacity issues identified in the study.
Certified Inspection and Condition Assessment
WRMA's engineers and inspectors hold certifications in sewer condition assessment from the National Association of Sewer Service Companies (NASSCO) and are experienced in the condition assessment of sewer pipelines, manholes and lateral service pipes for sanitary and stormwater applications.